I'm pleasantly surprised to see guys on here recommending the natural route. Google magnesium and mental health, magnesium is HUGELY overlooked in this respect, any form that ends in "ate" is good, using multiple forms is best, magnesium flake baths, transdermal magnesium, magnesium glycinate etc.
L-theanine is greattttt stuff that will boost dopamine, serotonin and gaba, just make sure that the one you buy says "suntheanine" on the bottle, this is the patented form, some companies are cutting corners and throwing in d-theanine I found this out recently when switching from Thorne brand to Now, it doesn't feel nearly as good.
Cognitive behavioural therapy, emotional freedom technique etc would be wise to look into, to really change your anxiety you need to not only support brain chemistry but also change the way you think.